Process of preparing artificial textile products with reduced luster from cellulose compounds



Patented ea. 29, 1931 TENT OFFlCE SAMUEL ISIDOOB. vLns, or ARNHEM, NETHERLANDS PROCESS OF PREPARING ARTIFICIAL TEXTILE PRODUCTS WITH REDUCED LUSTER FROM GELLULOSE COMPOUNDS No Drawing. Application filed September 21, 1927, Serial No. 221,150, and in the Netherlands May 28, 1927.

' 1 due to the evaporation of the volatile solvent.

As examples of solutions of cellulose compounds which I may use the following are given: cellulose acetate, cellulose nitrate, nitro-acetyl cellulose, alkyl-, aryl-, or aralkyl '2 ethers of cellulose, in acetone, ether, alcoholether, acetic acid and other mixed or nonmixed ethers or esters of cellulose in volatile solvents or mixtures of solvents.

In order to obtain a wool-like product from cellulose acetate it has already been proposed to treat the product, in the form of hanks, with warm or boiling water, solutions of ammonium, potassium, or calcium rhodanide, etc. One disadvantage of this method lies in the fact that a special after-treatment of the finished spun product and also washing and drying are necessary. Further disadvantages are that the spun product becomes too wool-like, and that the hanks shrink and otter become intermingled.

The object of my present invention is to provide a process whereby it is possible to obtain artificial textile products with reduced luster from cellulose directly (i. e. without any after-treatment and also to obtain any degree of reduction of the luster.

According to my invention the said result is obtained by carrying out the spinning process in the presence of water, which term also includes water vapour, in the use of the so called drying or evaporative method.

My invention may be realized in difierent ways. A. sufiicient amount of water may be maintained in the spinning cell, and the spun I be added if a duller product is desired, and a material may be introduced, before the threads are wholly deprived of the solvent, into a second room in which suflicient water vapour is present. r

Further, the object in View may be attained by using a spinning solution to which water has been added and of which theviscosity' has been brought back to the normal. In order that my invention may be clearly understood, the following example of a solution of cellulose acetate in acetone will now be described.

The solution of cellulose acetate in aceton is introduced into a spinning cell in a downward direction, through fine apertures, the spun material being led along a thread guide to the winding apparatus. The spinning process is carried out in the presence of water or, alternatively, in the presence of water vapour.

The spinning process may be carried'out 'in such a way that water vapour is present in the spinning'cell, the amount of water vapour increasing with the rise of temperature.

Alternatively, water vapour is not introduced into the spinning cell, the spun material being led out of the spinning cell before the solvent is completely removed, and

being then led into a room in which water vapour is present.

I may, for example, use a second cell or the winding apparatus may be arranged in a moist atmosphere or the'spun material may be freed from the acetone in a room inwhich water vapour is present, during its travel from the spinning cell to the winding apparatus.

The product obtained will be more or less "dull, the degree of dullness depending upon the length of the way over which the spun material is led into the damp atmosphere and also upon thedegree of humidity and the temperature of the air. I v I A small proportion of water may also be added to the spinning solution, the proportion of water depending amongst other things, upon the degree of dullness which is desired to be attained andupon the temperature in the spinning cell."

In general, a greater amount'of water must cellulose acetate in 100 litres of acetone is pre pared, and 2 litres of water are added thereto. The viscosity decreases, for instance, from to 20 (measured by the aid of a fall'- ing glass ball), and by the addition of 5 litres of benzene the viscosity of 80 is restored.

Thereafter, the solution is spun in a spinning cell, in which a temperature of 3040 C. prevails, whereby a dull silk is obtained.

If the temperature is raised to 4050 C. the silk becomes glossy, so that more water has to be added, and, in order to maintain the same viscosity, also more benzene.

Finally, several of the methods described above may be combined by regulating the moisture contained in the air in connection with the water contained in the spinning solution. The more humid the air. in the spinning cell, the less water is required to be added to the spinning solution, at the same temperature of the spinning cell. 7 From the above it will be clear that owing to the large number ofvariable factors, my present process for the preparation of artificial silk with reduced luster, may be regulated within very wide limits, thus enabling under any circumstance, the most favourable conditions possible to be chosen, which is a great advantage of my said process. Furthermore, is is unnecessary to make any alterations in the apparatus, and, in contradistinction to the known process referred to above no special after-treatment is necessary.

I claim:

1. A process for the preparation of artificial textile products with diminished luster from cellulose compounds, consisting of dissolving the cellulose compound in a volatile solvent, introducing the solution into a spinning cell, evaporating the volatile solvent the spinning cell, the proportion of such water being dependent upon the degree of dullness required in the product.

In testimony whereof I affix my signature.

SAMUEL ISIDOOR VLES.

therefrom by a spinning action, and leading solving a'solution of the cellulose compound in a volatile solvent, introducing the solution the spun material into an atmosphere into which a predetermined proportion of water isv ill) 

